Same, but probably Eye-ther most commonly for me. From South east.For some reason EE-ther puts me in mind of the west country
I've definitely said both as a speaker of General American. Gershwin even has it in a song lyric written in the 1930s. https://en.wikipedia.org/wiki/Let%27s_Call_the_Whole_Thing_Off#Full_list_of_differences
Is this actually a dialect thing? I'm pretty sure I switch between them both with no real logic.
Same, but probably Eye-ther most commonly for me. From South east.
For some reason EE-ther puts me in mind of the west country